Wong B S, Pan T, Liu T, Li R, Gambetti P, Sy M S
Division of Neuropathology, Institute of Pathology, Cancer Research Center, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA.
Biochem Biophys Res Commun. 2000 Jun 24;273(1):136-9. doi: 10.1006/bbrc.2000.2911.
Normal prion protein (PrP(C)) is a copper binding protein and may play a role in cellular resistance to oxidative stress. Recently, copper-bound recombinant PrP(C) has been shown to exhibit superoxide dismutase (SOD)-like activity. However, as PrP(C) affinity for copper is low in comparison to other cupro-proteins, the question remains as to whether PrP(C) could contribute SOD activity in vivo. To unravel this enigma, we compared the SOD activity in lysates extracted from different regions of the brain from wild-type mice before and after the depletion of PrP(C). We found that removal of PrP(C) from the brain lysates reduced the levels of total SOD activity. The level of contribution to the total SOD activity was correlated to the level of PrP expressed and to the predominant form of PrP present in the specific brain region. Collectively, these results provide strong evidence that PrP(C) differentially contributes to the total SOD activity in vivo.
正常朊病毒蛋白（PrP(C)）是一种铜结合蛋白，可能在细胞对氧化应激的抗性中发挥作用。最近，已证明铜结合的重组PrP(C)具有超氧化物歧化酶（SOD）样活性。然而，由于与其他铜蛋白相比，PrP(C)对铜的亲和力较低，PrP(C)是否能在体内发挥SOD活性仍是个问题。为了解开这个谜团，我们比较了野生型小鼠PrP(C)缺失前后从大脑不同区域提取的裂解物中的SOD活性。我们发现从脑裂解物中去除PrP(C)会降低总SOD活性水平。对总SOD活性的贡献水平与PrP的表达水平以及特定脑区中存在的PrP的主要形式相关。总体而言，这些结果提供了强有力的证据，表明PrP(C)在体内对总SOD活性有不同的贡献。
